SANTIAGO, Chile (AP) — U.S. experts on Chile’s dictatorship-era human rights violations said Monday that a judicial investigation into the death of poet Pablo Neruda risks going off track if it seriously looks at Michael Townley, an American who later worked as an assassin for Chile’s spy chief.

Townley was a violent right-wing militant who grew up in Chile in the 1960s and spread propaganda against Neruda’s great friend, Marxist President Salvador Allende, in early 1973. But experts said Townley was in Florida at the time of Neruda’s death on Sept. 23, 1973, just 12 days after Gen. Augusto Pinochet’s military coup ousted Allende. And contrary to the self-serving story put out by Pinochet’s spy chief, Townley was never a CIA agent, they said.

There’s a long paper trail including a Florida driver’s license, a new U.S. passport and salary receipts from a garage where Townley worked as a mechanic that proves he was in Florida in September 1973, said John Dinges, a journalist who covered Chile for The Washington Post and wrote about Townley in two books, “The Condor Years” and “Assassination on Embassy Row.”

Peter Kornbluh, the author of “The Pinochet File, a Declassified Dossier on Atrocity and Accountability,” also discounted the idea that Townley was worth looking into.

“We all want to see this case solved, but false leads are not going to bring us any closer to arriving at the truth of Pablo Neruda’s very untimely death,” Kornbluh said.

Both spoke with The Associated Press in phone interviews from the United States on Monday.

Neruda had been suffering from cancer and the disease was listed as the official cause of his death, but the poet’s driver and others close to him have long suspected foul play.

Nearly 40 years later, Judge Mario Carroza is formally investigating the cause of death of the Nobel Prize-winning poet, who would have been one of Pinochet’s most forceful critics if he had escaped Chile. His body has been disinterred for chemical tests, and Carroza is seeking any evidence available.

A key witness has been Dr. Sergio Draper, who attended Neruda at the hospital. Draper said in the 1970s that he was at Neruda’s side when he died. But Draper recently told the judge a different story — that a “Dr. Price” took over Neruda’s care just before he died, and disappeared shortly thereafter.

The judge ordered a police sketch based on Draper’s recollections to help identify this mysterious figure, and the AP obtained a copy of it Monday. Police notes below the black-and-white sketch describe the subject as about 28 years old, with blue eyes, white skin and short blond hair.

Draper treated both Neruda and former President Eduardo Frei Montalva, another Pinochet critic who died under suspicious circumstances while hospitalized. He has long denied any foul play in either death, and publicly insisted that Neruda was brought to the hospital near death from metastatic cancer.

Communist Party attorney Eduardo Contreras, who pushed for the Neruda investigation and has access to the closed-door testimony, told the AP that Draper’s description of “Dr. Price” could match either Townley or Harmutt Hopp. He said he wants Interpol to authoritatively determine where Townley was in September 1973.

“During the dictatorship many people entered and left Chile without their movements being registered,” Contreras said.

Unlike Townley, who had light brown hair, Hopp was a doctor, and blond. Hopp was sentenced in absentia in January to five years in prison for sexually abusing minors at Colonia Dignidad, a compound led by a former Nazi that doubled as one of Pinochet’s torture centers. But Hopp remains free after fleeing to Germany, which refused Chile’s extradition request.

Townley, who joined Chile’s DINA intelligence agency in June 1974, has said he acted on the orders of Pinochet’s spy chief, Manuel Contreras, when he planted bombs that killed critics of the dictatorship, including Gen. Carlos Prats in Buenos Aires and Chilean Ambassador Orlando Letelier in Washington.

Eduardo Contreras, who is not related to the ex-spy chief, repeated the often-told story that Townley was a “double-agent” who worked for the CIA as well as DINA. But both Dinges and Kornbluh said that the CIA twice turned down Townley’s efforts to join the agency and that Pinochet’s spy chief sought to divert culpability for his crimes by putting out the false story that the CIA had planted Townley inside Chile’s secret police.

“This is a story that Manuel Contreras has been putting out consistently since the death of Letelier: that Townley was not working for DINA but for the CIA. And the left falls into the trap again and again, because they want to throw mud at the CIA,” Dinges said.

Townley testified in the United States against Manuel Contreras, who is serving multiple life sentences for kidnappings and murders during the 1973-90 Pinochet dictatorship. Townley himself served a six-year sentence in the U.S. for the Letelier bombing and then was put into the witness protection program.

U.S. federal investigations showed that Townley fled Chile months before the coup because he feared arrest for murdering a homeless man who got in the way of an anti-Allende operation. Dinges said Townley didn’t return to Chile until Oct. 18, 1973, carrying the same false passport that he would later use to enter Argentina and kill Prats.